Nothing in Nature is random. A thing appears random only through the incompleteness of our knowledge. - Benedictus de Spinoza

The work of the popularizer, though sometimes depreciated by professional students, is a very useful and necessary work, and in few cases more useful or more necessary than in the case of Spinoza. For, although Spinoza is often so difficult that even the best philosophers cannot be sure of having understood him, the essence of his doctrine is capable of being interesting and profitable to many who cannot devote themselves to metaphysics. Although the task of interpretation has been admirably performed for the technical reader by Mr. Joachim, and for a wider class by Sir Frederick Pollock, there must be many who will be grateful for the chance of reading the Ethics itself, without having to work their way through Spinoza's Latin.

Baruch Spinoza, the 17th-century Dutch thinker, may be among the more enigmatic (and mythologized) philosophers in Western thought, but he also remains one of the most relevant, to his time and to ours. He was an eloquent proponent of a secular, democratic society, and was the strongest advocate for freedom and tolerance in the early modern period. The ultimate goal of his “Theological-Political Treatise” — published anonymously to great alarm in 1670, when it was called by one of its many critics “a book forged in hell by the devil himself”— is enshrined both in the book's subtitle and in the argument of its final chapter: to show that the “freedom of philosophizing” not only can be granted “without detriment to public peace, to piety, and to the right of the sovereign, but also that it must be granted if these are to be preserved.”

It is an amazing thing that our memory best retains images of great philosophers when their lives were coming to an end. Socrates raising the chalice with hemlock to his mouth, Seneca whose veins were opened by a slave (there is a painting of this by Rubens), Descartes roaming cold palace rooms with a foreboding that his role of teacher of the Swedish Queen would be his last, old Kant smelling a grated horseradish before his daily walk (the cane preceding him, sinking deeper and deeper into the sand), Spinoza consumed by tuberculosis and patiently polishing lenses, so weak he is unable to finish his Treatise on the Rainbow.